The present invention relates to a responser in an IC card communication system and a communication module used for it, and particularly to a responser or the like used for both of contact and non-contact applications.
A communication system employing the IC card is applied to prepaid cards, lifts of the ski resorts, automatic ticket inspection at the railroad gates, automatic goods sorting and the like. Examples of the IC card are, a contact type IC card having a contact terminal connected to an IC embedded in a card through which power supply and data interchange are carried out, a non-contact type IC card using electromagnetic waves for power supply and data interchange, and a single IC card combining both of the contact and non-contact applications.
An example of a conventional IC card 2 used for both of the contact and non-contact applications (one coil type) is illustrated in FIG. 20. A circuit board 4 is placed within IC card 2 shown in FIG. 20. An IC chip 8 is placed at the lower surface of circuit board 4, and a metallic contact terminal 6 is formed at the upper surface of circuit board 4. IC chip 8 is electrically connected to contact terminal 6. Contact terminal 6 is formed to be exposed at the surface of IC card 2. IC card 2 receives power from and communicates data with a contact type reader/writer (interrogator (not shown)) through contact terminal 6. A control circuit (not shown) provided in IC chip 8 decodes data to rewrite data in a nonvolatile memory (not shown) provided in IC chip 8 and responds to the contact type reader/writer.
An antenna 10 is also placed in IC card 2. Antenna 10 is electrically connected to IC chip 8 via a wire 12. IC card 2 receives, at a resonance circuit (not shown) including antenna 10, electromagnetic waves transmitted from a non-contact type reader/writer (not shown) for using them as power source. IC card 2 also receives data multiplexed on the electromagnetic waves and transmitted. Response is made by changing the impedance of the resonance circuit. The non-contact type reader/writer finds the content of the response by detecting impedance change (impedance reflection) of its resonance circuit (not shown) caused by impedance change of the resonance circuit of IC card 2.
It is therefore advantageous to employ IC card 2 used for both of the contact and non-contact applications since communication is possible whether the reader/writer is the contact type or the non-contact type.
However, following problems arise in such a conventional IC card 2 which is used for both of the contact and non-contact applications as described above. For the conventional IC card 2, circuit board 4 provided with contact terminal 6 and IC chip 8 as well as antenna 10 should be prepared separately, and these should be electrically connected by wire 12. As a result, the manufacturing process of IC card 2 becomes complicated to cause increase in the manufacturing cost of IC card 2. In addition, a malfunction is likely to occur due to disconnection of wire 12 resulting from deformation of IC card 2, leading to relatively low reliability of the IC card.
An object of the present invention is to solve such problems of the conventional IC card used for both of the contact and non-contact applications, and provide a responser with low cost and high reliability as well as a communication module used for it.
According to the present invention, a responser capable of communicating with an interrogator is provided with a communication module. The communication module includes a circuit board, a contact terminal, an antenna, and a processing circuit. The contact terminal is provided to the circuit board and in electrical contact with the interrogator. The antenna is provided to the circuit board and receives electromagnetic waves from the interrogator. The processing circuit is provided to the circuit board and connected to the contact terminal and the antenna to process a signal supplied from the interrogator via the contact terminal or the antenna and a signal to be supplied to the interrogator via the contact terminal or the antenna.
In such a communication module, the contact terminal, the antenna, and the processing circuit are provided to the same circuit board, so that the communication module is assembled in a box container highly easily. Consequently, reduction of occurrence of defective products in the assembly work as well as reduction in the assembly cost are possible. Further, since a wire for connecting the antenna to the circuit board is unnecessary, a defect such as the wire disconnection does not happen even if a strong force is applied to the responser. In addition, since the antenna is provided to the circuit board, the circuit board is resistant to bending, twisting and the like.
Preferably, the contact terminal is provided to one surface of the circuit board, and the antenna and the processing circuit are provided to the other surface of the circuit board. Accordingly, the communication module is made more compact.
Preferably, the antenna is directly formed on the circuit board. The antenna can thus be formed easily on the circuit board using the general etching technique.
Preferably, the processing circuit includes a switching unit and a setting unit. The switching unit switches resonance frequency of the antenna. The setting unit sets a switching manner of the switching unit to obtain a desired level of an output from the antenna. Accordingly, the resonance frequency can be adjusted automatically regardless of the material, shape or size of the contact terminal, or the positional relation and distance between the contact terminal and the antenna, or the like.